b) Based on the information it this table, the daily waste remained the same but the total waste has steadily increased. What are some possible explanations for this?

x would be the most and the least would be y because there are more fruit   and seeds than flock z has insects

the correct answer is: b. pantala flavescens, because these organisms would have a high level of genetic variation due to sexual reproduction.  

because involves two organisms (parents) whose genetic material combines, sexual reproduction leads to genetic variation in new generations of offspring. the offspring is an unique organism, with new genome, more protected with the higher ability to adapted. this process is fundamental to evolution.